Burglar-alarm plates.



G. DZERM A.

BURGLAR ALARM PLATES.

APPLICATION FILED NOV. 4,1909

Patented Mar. 21, 1911;

G. DZERMA. BURGLAB ALARM PLATES.

- APPLICATION FILED NOV. 4,1909. 987,220, Patented Mar. 21, 1911 2SKEETSSHEET 2.

Tu naRRls PETERS 50., wasumarou, n c.

GUSTAV DZERMA, F BELLE'FONTAINE, OHIO.

BURGLAR-ALARM PLATES.

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Application filed November 4, 1809.

To (all whom it may concern.

Be it known that I, Gusrav DZ'ERMA, a citizen oi the United States,residing at Belletontaine, in the county of Logan and tate of Ohio, haveinvented a new and useful lniproveinent in Burglar-Alarm Plates, ofwhich the following is a specification.

This invention relates to a burglar alarm and name especially to contactplates constructed, arranged and insulated in a particular manner,thereby adapting them for use in a particular manner.

Tile, object of the invention is to provide means for sounding an alarmin case any one ascends stairway, or walks upon or across anypredetermined floor or space.

The invention consists of a plurality of metal plates spaced apart, twoof said plates being connected in an electric circuit, said plates beingsuitably cut out and carrying a plurality of spring plates arranged inparallel rows, or otherwise as may be desired, an electric circuit beingcompleted by pressure of the foot upon any one of: the spring plates.

.ln the accompanying drawings, Figure 1 is a plan vie v of one of mydevices. Fig. 2 is an enlarged plan view of a corner portion, a springplate being omitted. Fig. 3 is a plan view or a corner portion of aninner metal plate. l ig. 4t is a plan view of a corner portion of abottom plate. Figs. 5 and 6 are plan views 01 corner portions of sheetsof insulation. Fig. 7 is an enlarged sectional view upon the line 77 ofFig. 1.

The invention can be employed in a number or different ways but consistsessentially of a metal plate 1 of any desired size which plate has itscorner portions cut out as shown at 2. This plate is provided with aplurality of longitudinally extending openings 3 arranged preferably inparallel rows, the openings in one row being staggered with respect tothose in an adjacent row, and for this reason prefer to place an evennumber of openings 'in one row and an odd number in the adjacent row, asshown in Fig. 1. Transverse slots 1 are formed in the plate at oppositeen ls oi: the openings 3, and the metal separating said slots from theopenings is slightly depressed, thus forming a series of bridges 5 whichare slightly below tie plane of the upper face of the plate 1. A secondplate 6 also of metal is employed and this plate is of less size thanthe plate 1, and its corner portions project from be- Specifieation ofLetters Patent.

Patented Mar. 231, 12 31.1.

Serial No. 526,264.

neath the plate 1, owing to the corners of said plate 1 being cut awayas shown at 2.

The plate 6 is provided with openings 7 which aline with and are largerthan the slots 1-. The openings 7 are arranged in pairs and between eachpair of openings are cut segmental slots 8, a metal portion 9 being leftbetween the slots 8 and extending between the openings 7 of each pair ofopenings, said portions 9 of the plate 6 lying immediately beneath theopenings 3 of the plate 1.

A base plate 10 substantially of the same size as the plate 1 but withits corner portions intact has tongues 11 punched upwardly from it, saidtongues being arranged in pairs, the tongues of each pair extendingtoward each other. Slightly curved spring plates 12 extendlongitudinally across the openings 3 of the plate 1 and have their endportions passed through the slots resting upon the bridges 5, said endportions passing through the openings 7, and owing to the size of saidopenings being spaced from the plate 6, and the end portions of eachspring are held by a pair oi": the tongues 11 of the plate 10. Toinsulate the plates from each other I place sheet of insi'ilatingmaterial 18 between plates 1 and 6 said sheet of insulating materialbeing cut out as shown at 1 1, and the out out portions registering withthe openings 3 of plate 1 and also with the openings 7 of plate 6. Theplate 10 is also insulated from plate 6 by a sheet of insulatingmaterial 15 which is provided with cut out portions 16 which registerwith the openings 7, but are slightly smaller, and through which thetongues 11 project to receive the ends of the springs 12. These partsare secured firmly together by binding over one or more ed es of theplate 1, as shown in Fig. 7 and the various plates are provided withsuitable openings 17 through which nails, screws, or thread may bepassed in order to secure the completed plate in position.

ll desired the entire device may be inclosed in any suitable fabric. Toconnect the plate in an electric circuit, which circuit may also includeany form of electric alarm device, wires 18 are secured respectively toan end portion of the plate 1 and to a corner portion of the plate 6,the wires being connected at opposite ends of the complete device, andit will be obvious that upon pres sure Of any of the springs 12 theywill be brought into contact through the openings 3 and ll with themetal portion 9 of plate 3,

thus electrically connecting the two plates together and completing theelectric circuit. Plate. as shown in Fig. 1 may be secured by nails, orcrews upon the steps of a stairway, being or" such size as topractically cover a step, and may or may notbe covered by a staircarpet. Such plates may also be placed beneath portions of a carpet in aroom, either in front of a door, or a window or in front of some articleof furniture or plates of this design may be sewn upon the undersides ofrugs and thereby rendered capable of ready removal from one part of aroom to another, or from one portion of a building to another.

What I claim is 1. A device of the kind described comprising an upper, abase and an intermediate plate, the upper plate having an openingtherein, the intermediate plate having openings therein, and a springplate having its ends in contact with the base plate and said springplate being in electrical contact with the upper plate, and bridging theopening of the upper plate, said spring plate passing through theopenings in the intermediate plate, the said upper and intermediateplates being connected respectively to branches of an electric circuitand the intermediate plate being insulated from the two other plates.

A. device of the kind described comprising an upper, an intermediate,and a base plate, the intermediate plate being insulated from the upperplate and from the base plate and having openings therein, and the upperand intermediate plates being connected respectively to parts of anelectric circuit, the upper plate having a plurality of openings formedtherein, and a plurality of spring plates passing loosely through theintermediate and the upper plates and in electrical contact with theupper plate, each spring plate bridging one of the openings formed inthe upper plate and being depressible therethrough into contact with theintermediate plate.

3. A device of the kind described comprising two superimposed platesinsulated from each other, the upper plate having a plurality ofopenings arranged in parallel rows, the openings of one row beingstaggered with respect to those of the other, spring plates, each ofsaid spring plates bridging one of the openings and in electricalcontact with said upper plate, and being depressible by the foot intoengagement with the other plate, and an electric circuit including saidplates.

at. A device of the kind described comprising a base plate havingtongues punched therein, an upper plate, an intermediate plate, openingsbeing formed in the intermediate plate to receive said tongues, theupper plate having an opening with slots formed adjacent the ends of theopening, a spring plate bridging the last mentioned opening, the endportions of the spring plate passing through the slots and the openingsin the intermediate plate and engaging the tongues of the base plate,and an electric circuit in which the said upper and intermediate platesare included, the intermediate plate being insulated from the upper andfrom the lower plate.

5. A device of the kind described comprising an upper plate having aplurality of longitudinally extending openings formed therein inparallel rows, the openings in one row being staggered with respect tothose in an adjacent row, transverse slots being formed in said plateadjacent opposite ends of each of said openings, and the strips spacingsaid slots from the adjacent opening being depressed, a base plate,tongues arranged in pairs and carried by said base plate, anintermediate plate, said plate being provided with openings adapted toregister with the slots of the upper plate and with the tongues of thebase, and spring plates having their ends in engagement with saidtongues, said spring plates passing through the slots of the upper andthe openings of the intermediate plates and extending longitudinallyacross the openings of the upper plate, the intermediate plate beinginsulated,

from the upper and base plates, said upper and intermediate plates beingadapted to form parts of an electric circuit.

GUSTAV DZERB IA. lVitnesses A. T. Coon, NANNIE S. GAssmY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

